No description available.

No description available.

Monitoring water quality on a near-real-time basis to address water resources management and public health concerns in coupled natural systems and the built environment is by no means an easy task. Furthermore, this emerging societal challenge will continue to grow, due to the ever-increasing anthropogenic impacts upon surface waters. For example, urban growth and agricultural operations have led to an influx of nutrients into surface waters stimulating harmful algal bloom formation, and stormwater runoff from urban areas contributes to the accumulation of total organic carbon (TOC) in surface waters. TOC in surface waters is a known precursor of disinfection byproducts in drinking water treatment, and microcystin is a potent hepatotoxin produced by the bacteria Microcystis, which can form expansive algal blooms in eutrophied lakes. Due to the ecological impacts and human health hazards posed by TOC and microcystin, it is imperative that municipal decision makers and water treatment plant operators are equipped with a rapid and economical means to track and measure these substances. Remote sensing is an emergent solution for monitoring and measuring changes to the earth’s environment. This technology allows for large regions anywhere on the globe to be observed on a frequent basis. This study demonstrates the prototype of a near-real-time early warning system using Integrated Data Fusion and Mining (IDFM) techniques with the aid of both multispectral (Landsat and MODIS) and hyperspectral (MERIS) satellite sensors to determine spatiotemporal distributions of TOC and microcystin. Landsat satellite imageries have high spatial resolution, but such application suffers from a long overpass interval of 16 days. On the other hand, free coarse resolution sensors with daily revisit times, such as MODIS, are incapable of providing detailed water quality information because of low spatial resolution. This iv issue can be resolved by using data or sensor fusion techniques, an instrumental part of IDFM, in which the high spatial resolution of Landsat and the high temporal resolution of MODIS imageries are fused and analyzed by a suite of regression models to optimally produce synthetic images with both high spatial and temporal resolutions. The same techniques are applied to the hyperspectral sensor MERIS with the aid of the MODIS ocean color bands to generate fused images with enhanced spatial, temporal, and spectral properties. The performance of the data mining models derived using fused hyperspectral and fused multispectral data are quantified using four statistical indices. The second task compared traditional two-band models against more powerful data mining models for TOC and microcystin prediction. The use of IDFM is illustrated for monitoring microcystin concentrations in Lake Erie (large lake), and it is applied for TOC monitoring in Harsha Lake (small lake). Analysis confirmed that data mining methods excelled beyond two-band models at accurately estimating TOC and microcystin concentrations in lakes, and the more detailed spectral reflectance data offered by hyperspectral sensors produced a noticeable increase in accuracy for the retrieval of water quality parameters.

No description available.

No description available.

No description available.

Due to an ever-increasing global population and limited resource availability, there is a constant need for detection of both natural and anthropogenic hazards in water, air, food, and material goods. Traditionally a different instrument would be used to detect each class of contaminant, often after a concentration or separation protocol to extract the analyte from its matrix. Raman spectroscopy is unique in its ability to detect organic or inorganic, airborne or waterborne, and embedded or adsorbed analytes within environmental systems. This ability comes from the inherent abilities of the Raman spectrometer combined with concentration, separation, and signal enhancement provided by drop coating deposition Raman (DCDR) and surface-enhanced Raman spectroscopy (SERS). Herein the capacity of DCDR to differentiate between cyanotoxin variants in aqueous solutions was demonstrated using principal component analysis (PCA) to statistically demonstrate spectral differentiation. A set of rules was outlined based on Raman peak ratios to allow an inexperienced user to determine the toxin variant identity from its Raman spectrum. DCDR was also employed for microcystin-LR (MC-LR) detection in environmental waters at environmentally relevant concentrations, after pre-concentration with solid-phase extraction (SPE). In a cellulose matrix, SERS and normal Raman spectral imaging revealed nanoparticle transport and deposition patterns, illustrating that nanoparticle surface coating dictated the observed transport properties. Both SERS spectral imaging and insight into analyte transport in wax-printed paper microfluidic channels will ultimately be useful for microfluidic paper-based analytical device (𝜇PAD) development. Within algal cells, SERS produced 3D cellular images in the presence of intracellularly biosynthesized gold nanoparticles (AuNP), documenting in detail the molecular vibrations of biomolecules at the AuNP surfaces. Molecules involved in nanoparticle biosynthesis were identified at AuNP surfaces within algal cells, thus aiding in mechanism elucidation. The capabilities of Raman spectroscopy are endless, especially in light of SERS tag design, coordinating detection of analytes that do not inherently produce strong Raman vibrations. The increase in portable Raman spectrometer availability will only facilitate cheaper, more frequent application of Raman spectrometry both in the field and the lab. The tremendous detection power of the Raman spectrometer cannot be ignored. / Ph. D.

Diese Dissertation ist ein Beitrag zum Forschungsfeld der Stressökologie, im Spe-ziellen der Verhaltensökotoxikologie. Das spontane lokomotorische Verhalten der Fischarten Danio rerio und Leucaspius delineatus wurde unter sublethaler Expo-sition mit dem Cyanobakterientoxin Microcystin-LR (MC-LR) und dem Xenobio-tikums 2.4.4`-Trichlorobiphenyl (PCB 28) quantifiziert. Die Schwimmgeschwin-digkeit und Anzahl der Wendungen wurden kontinuierlich mit einem automati-schen Video-Monitoringsystem unter Laborbedingungen aufgezeichnet. In Hin-blick auf zyklische Aspekte wurden die Verhaltensanalysen mit chronobiologi-schen Methoden kombiniert. Hiermit wurde gezeigt, dass MC-LR und PCB 28 zu signifikanten Effekten in Verhalten und Aktivitätsrhythmik beider Fischarten führten. Höhere Konzentrati-onen beider Untersuchungssubstanzen verursachten eine deutliche Aktivitätsredu-zierung bei Danio rerio und Leucaspius delineatus. Einige der festgestellten Do-sis-Wirkungsbeziehungen entsprechen der Hormesistheorie, z. B. war bei geringe-ren MC-LR Konzentrationen ein Aktivitätsanstieg und bei höheren ein Aktivitäts-abfall beider Fischarten zu verzeichnen. Die Exposition mit MC-LR und PCB 28 verringerte bei beiden Testfischarten die Synchronisation der Aktivität mit dem Zeitgeber Licht. Dies führte bei beiden Fischarten zu einer Phasenverschiebung. Bei Leucaspius delineatus war unter dem Einfluss von MC-LR eine Phasenumkehr zu verzeichnen, die Fische wechselten von Tag- zu Nachtaktivität. Die Cosinor Analyse zeigte Dosis abhängige Veränderungen der circadianen Rhythmen der Schwimmaktivität (z.B. MESOR, Akrophase) unter Einfluss von MC-LR und PCB 28 an. Die Power Spektral Analyse indizierte für beide Fischar-ten unter Einwirkung von MC-LR and PCB 28 eine reduzierte Dominanz des cir-cadianen Rhythmuspeaks. Da die registrierten Unterschiede in der Reaktion beider Fischarten auf MC-LR und PCB 28 eher gering waren, sind Ergebnisse der Art Danio rerio, die häufig in Toxizitätstests verwendet wird, mit denen der einheimischen Art Leucaspius deli-neatus vergleichbar. Die Ergebnisse belegen, dass Verhaltensuntersuchungen in Kombination mit chronobiologischen Auswertemethoden eine sensitive und zuverlässige Abschät-zung des Gefährdungspotentials von Substanzen sowohl auf dem Gebiet der Öko-toxikologie als auch für Biomonitoring ermöglichen. / This thesis contributes to the field of stress ecology specifically behavioural ecotoxicology. The spontaneous locomotor behavior of two fish species Danio re-rio and Leucaspius delineatus was recorded and quantified continuously under sublethal exposure to the cyanotoxin microcystin-LR (MC-LR) and the xenobioti-cum 2.4.4`-trichlorobiphenyl (PCB 28). By using an automated video-monitoring system, the swimming velocity and the number of turns were assessed under labo-ratory conditions. For analysing cyclic aspects basic behavioural analyses were combined with chronobiological procedures as cosinor analysis and power spec-tral analysis. Both MC-LR and PCB 28 acted as stressors and caused significant changes in the behaviour and circadian activity rhythms of Danio rerio as well as Leucaspius de-lineatus. So for both species elevated concentrations of the stressors led to a re-duction of their activity. Some dose-responses correspond to the hormesis theory, e.g., there was an increase of daytime activity at lower MC-LR concentrations and a decrease at elevated concentrations of MC-LR for both species. A degree of desynchronisation of activity to the zeitgeber light, which led to a phase shift was caused by the chemicals in both fish species. In Leucaspius de-lineatus this shift was so drastic that this species reversed their significant diurnal activity and became nocturnal under the influence of MC-LR. The Cosinor analysis revealed MC-LR- and PCB 28-induced, dose-dependent al-terations of the circadian rhythms of activity (e.g., MESOR, acrophase). The power spectral analysis showed that the dominance of the circadian rhythmic peak (of 24 h) was reduced under MC-LR and PCB 28 for both species. Since the observed differences in the reactions of both species to MC-LR and PCB 28 were rather small, the results of the species Danio rerio which is widely used for environmental risk assessment tests, are comparable to those of the native European species Leucaspius delineatus. The findings of this study proved that the basic behavioural analyses combined with chronobiological procedures could be valuable tools for the study of stressful or even harmful environmental factors in the field of ecotoxicology as well as for biomonitoring.

O presente trabalho de pesquisa teve como objetivo principal avaliar a remoção de fitoplancton e microcistina em cinco fluxogramas de tratamento de água para abastecimento, que tiveram como seqüência básica as etapas de coagulação, floculação, flotação por ar dissolvido e filtração, complementados com oxidação química em diferentes pontos da seqüência básica de tratamento estabelecida. Os ensaios foram realizados em escala de laboratório, utilizando água de estudo preparada mediante a mistura de água coletada no reservatório de Barra Bonita, no Estado de São Paulo, e cultura com elevada concentração de microcistina preparada em laboratório. A concentração de microcistina na água de estudo foi mantida no intervalo de 14 a 17 µg/L. O cloreto férrico foi utilizado como agente coagulante, o permanganato de potássio e o cloro, na forma de hipoclorito de sódio, foram utilizados como agentes oxidantes. Foi observada eficiência de remoção de fitoplancton de cerca de 99,9% devido às etapas de coagulação, floculação e flotação por ar dissolvido e, conseqüentemente, remoção de microcistina contida no interior das células íntegras. A oxidação com cloro realizada após a filtração, bem como a oxidação com a associação do permanganato de potássio e cloro realizada após a flotação, resultaram em eficiência de remoção de microcistina extracelular (microcistina livre no meio líquido) da ordem de 95%, atendendo ao padrão de potabilidade com cocentrações de microcistina menores que 1,0 µg/L. A oxidação da água bruta com permanganato de potássio associada à oxidação da água flotada com cloro, apresentou o melhor desempenho de remoção de microcistina extracelular, com eficiência superior a 98%. Em todos os ensaios de oxidação química foi constatada a influência da variação do pH na remoção de microcistina, sendo que o aumento de eficiência foi associado à diminuição dos valores de pH. Foram observados indícios de remoção de trihalometanos pela flotação por ar dissolvido e redução da formação de trihalometanos quando a oxidação química foi feita com a associação do permanganato de potássio e cloro. / The aim of this research was to study the phytoplankton and microcystin removal at different treatment conditions, all based in coagulation, flocculation, dissolved air flotation and filtration, complemented by chemical oxidation applied at different points of the basic treatment sequency. The lab scale experiments was conduted with raw water prepared by a mixture of natural water, collected in Barra Bonita reservoir at São Paulo State, Brazil, and a high concentrated Microcystis culture prepared in laboratory. The microcystin concentration in raw water was kept in a range of 14 to 17 µg/L. Ferric chloride was used as coagulant, and, potassium permanganate and chlorine (sodium hypochlorite) were used as oxidants. The results showed phytoplankton removal efficiency about 99,9% by the sequency of coagulation, flocculation and dissolved air flotation, resulting a great removal of microcystin retained into the whole cells. The chlorine oxidation after filtration, as well as the oxidation with potassium permanganate and chlorine after dissolved air flotation, resulted in a microcystin removal of about 95% and concentrations under the World Health Organization drinking water guideline value of 1,0 µg/L. The raw water potassium permanganate oxidation associated with the chlorine oxidation after flotation, leaded to the best results concerning microcystin removal, with efficiency above 98%. All experimental conditions with chemical oxidation showed a relevant effect of the pH on the microcystin removal, the decrease of pH values contributed to the increase of microcystin removal. It was observed signs of THM´s removal by the dissolved air flotation and reduction of THM´s production when the chemical oxidation took place with the association of potassium permanganate and chlorine.

O presente trabalho teve como objetivo avaliar a remoção de três concentrações diferentes de microcistina extracelular em diferentes combinações de tratamento de águas para abastecimento, em escala de bancada, que tiveram como sequência básica a clarificação associada ou não aos processos de pré-oxidação com \'K\'MN\'O IND.4\', adsorção em CAP e pós-cloração. Os resultados mostraram que para todas as águas estudadas o permanganato de potássio não interferiu nos mecanismos de coagulação/floculação e ainda mostrou-se uma alternativa segura para realização da pré-oxidação no que tange à formação de THMs. Na Fase 1, com concentração inicial de microcistina extracelular em torno de 1,4 \'mü\'g/L, a clarificação (coagulação, floculação, flotação por ar dissolvido e clarificação final) atendeu ao padrão de potabilidade que determina concentrações de microcistina menores que 1,0 \'mü\'g/L. Já na Fase 2, com concentração inicial microcistina extracelular em torno de 21,7 \'mü\'g/L, para o atendimento à legislação foi necessário associar a clarificação à pré-oxidação, dosando-se 1,0 ou 2,0 mg \'K\'MN\'O IND.4\'/L, e à pós-cloração com 3,0 mg \'CL IND.2\'/L. Na Fase 3, com concentração inicial de microcistina extracelular em torno de 64,1 \'mü\'g/L, a associação da clarificação com a adsorção com 60,0 mg/L de CAP e com a pós-cloração com 3,0 mg \'CL IND.2\'/L proporcionou residuais de microcistina extracelular inferiores à 1,0 \'mü\'g/L. Observou-se ainda, que nas Fases 1 e 3 a presença de matéria orgânica dissolvida interferiu negativamente nas sequências de tratamento ao consumir parte do permanganato de potássio destinado à oxidação da microcistina extracelular. Entretanto, na Fase 2 a demanda do pré-oxidante pelas substâncias húmicas parece ter impedido a lise de parte das células de Microcystis sp. / The present work had as objective to evaluate the removal of three different concentrations of extracellular microcystins in different combinations of water treatment for supplying, in bench scale, that had as basic sequence the clarification associated or not with the processes of pre-oxidation with \'K\'MN\'O IND.4\', adsorption on PAC and post-chlorination. The results showed that for all waters studied the potassium permanganate did not interfere in the mechanisms of coagulation/flocculation and also proved to be a safe alternative for achieving the pre-oxidation with regard to the formation of THMs. In Phase 1, with initial concentration of extracellular microcystin around 1.4 \'mü\'g/L, the clarification (coagulation, flocculation, dissolved air flotation and clarification final) met the World Health Organization drinking water guideline value of 1.0 \'mü\'g/L of microcystin. Already, in Phase 2, with initial concentration extracellular microcystin around 21.7 \'mü\'g/L, to meet the legislation was necessary to involved the clarification with the pre-oxidation, dosing 1.0 or 2.0 mg \'K\'MN\'O IND.4\'/L, and with the post-chlorination with 3.0 mg \'CL IND.2\'/L. In Phase 3, with initial concentration of extracellular microcystin around 64.1 \'mü\'g/L, the association of clarification with the adsorption with 60.0 mg/L of PAC and the post-chlorination with 3.0 mg\'CL IND.2\'/L provided residual extracellular microcystin below 1.0 \'mü\'g/L. It was also observed that in Phases 1 and 3 the presence of dissolved organic matter intervened negatively in the sequence of treatment when consuming part of the potassium permanganate destined to the oxidation of extracellular microcystin. However, in Phase 2 the demand for pre-oxidizing by the humic substances seems to have prevented the lysis of some cells of Microcystis sp.